This invention relates generally to the field of medical stents. More specifically, the invention relates to techniques for deploying stents into vessels such that a side opening in the stent wall is aligned with an ostium of a branch vessel.
A type of endoprosthesis device, commonly referred to as a stent, may be placed or implanted within a vein, artery or other tubular body organ for treating occlusions, stenoses, or aneurysms of a vessel by reinforcing the wall of the vessel or by expanding the vessel. Stents have been used to treat dissections in blood vessel walls caused by balloon angioplasty of the coronary arteries as well as peripheral arteries and to improve angioplasty results by preventing elastic recoil and remodeling of the vessel wall. Two randomized multicenter trials have shown a lower restenosis rate in stent treated coronary arteries compared with balloon angioplasty alone (Serruys, P W et al., New England Journal of Medicine 331:489-495 (1994) and Fischman, D L et al. New England Journal of Medicine 331:496-501 (1994), the disclosures of which are herein incorporated by reference. Additionally, regular stents have been used at bifurcation lesions with limited success rates (Chevalier, B. et al. American Journal of Cardiology 82:943-949 (1998), Yamashita T. et al. Journal of American College of Cardiology 35:1145-1151 (2000) and Satler S. et al. Catheterization and Cardiovascular Interventions 50:411-412 (2000). Side branch jailing, fear of plaque shifting and total occlusion and difficulty of the procedure require novel, easier to use, special stents to be developed. Stents have been successfully implanted in the urinary tract, the bile duct, the esophagus and the tracheo-bronchial tree to reinforce those body organs, as well as implanted into the neurovascular, peripheral vascular, coronary, cardiac, and renal systems, among others. The term “stent” as used in this Application is a device that is intraluminally implanted within bodily vessels to reinforce collapsing, dissected, partially occluded, weakened, diseased or abnormally dilated or small segments of a vessel wall.
One of the drawbacks of conventional stents is that they are generally produced in a straight tubular configuration. The use of such stents to treat diseased vessels at or near a bifurcation (branch point) of a vessel may create a risk of compromising the degree of patency of the main vessel and/or its branches, or the bifurcation point and also limits the ability to insert a branch stent into the side branch if the result of treatment of the main, or main, vessel is suboptimal. Suboptimal results may occur as a result of several mechanisms, such as displacing diseased tissue, plaque shifting, snow plowing, chronic total occlusion, vessel spasm, dissection with or without intimal flaps, thrombosis, and embolism.
As described in related U.S. patent application Ser. No. 08/744,002 filed Nov. 4, 1996 (now abandoned), Ser. No. 09/007,265 filed Jan. 14, 1998, Ser. No. 08/935,383, filed Sep. 23, 1997, 60/088,301 filed Jun. 5, 1998, and Ser. No. 09/663,111, filed Sep. 15, 2000, and PCT Patent Application Publication No. WO 99/00835 filed Jan. 14, 1998, systems and methods have been developed for deploying a main stent in a main vessel at the intersection of a main vessel and a branch vessel. Further, a branch stent may be positioned within a branch vessel through a side opening in the main stent. The complete disclosures of all these references are herein incorporated by reference.
This invention relates to other novel techniques for deploying stents at such vessel intersections to permit the side opening to be aligned with the ostium of the branch vessel. Some embodiments are particularly directed toward managing the guidewires used to introduce the catheter systems to the region of interest.